For the dividends, you'll enter the 1099-DIV form by following this pathway: Federal Taxes > Wages & Income > Interest & Dividends > Dividends on 1099-DIV, and follow the prompts.
Your 1095-C does not have to be entered into TurboTax; just keep it for your records. But you'll still need to visit the Health Insurance section and answer the first two questions: whether you had coverage for the entire year, and whether you had one of the less common insurance policies (Marketplace/Obamacare).